Outcomes of cataract surgery in eyes with a low corneal endothelial cell density

Association Between Endothelial Cell Density and Corneal Thickness in Medium, Short, and Long Eyes of Han Chinese Cataract Patients

PURPOSE

To evaluate the association between the endothelial cell density (ECD) and central corneal thickness (CCT) in medium, short, and long eyes of preoperative Han Chinese cataract patients.

DESIGN

Retrospective cross-sectional study.

METHODS

We consecutively enrolled 410 eyes, namely, 50 short eyes (axial length [AL]<22.0 mm), 150 medium eyes (22.0≤AL<24.0 mm), 120 medium-long eyes (24.0≤AL<26.0 mm), and 90 long eyes (AL≥26.0 mm), of 410 adult patients scheduled for cataract surgery. The ECD and CCT were determined preoperatively with a noncontact specular microscope. The association between the CCT and ECD was identified by using a multivariable regression analysis. A thin cornea was defined as having a CCT less than 500 µm.

RESULTS

After adjusting for age, the presence of arterial hypertension, the presence of diabetes mellitus, intraocular pressure, and AL, a positive association between the CCT and ECD was identified in short eyes (linear regression coefficient [B]=3.40; standardized B [β]=0.52; P = .03), medium eyes (B = 2.33; β=0.28; P = .002), medium-long eyes (B = 1.84; β=0.25; P = .02), and long eyes (B = 2.69; β=0.41; P = .04). In the total group, the multivariable logistic analysis showed a significant link between the presence of a thin cornea and a lower ECD (odds ratio [OR]=0.80 per 100 cells/mm2 increase; P = .001).

CONCLUSIONS

For cataract patients of Han ethnicity, a significant association between a thin CCT and a lower ECD was shown across the AL spectrum and was most prominent in short eyes. Eyes with a thin cornea are more likely to have a lower ECD.

Corneal endothelial cell density and associated factors among adults at a regional referral hospital in Uganda: a cross-sectional study

BACKGROUND

To assess the prevalence of low corneal endothelial cell density and correlates of corneal endothelial cell density among adults attending Mbarara University and Referral Hospital Eye Centre in Uganda.

METHODS

In this hospital-based cross-sectional study, participants 18 years and older, were enrolled. We obtained informed consent, and basic demographic data. We also conducted visual acuity, a detailed slit lamp examination, intra-ocular pressure, corneal diameter, tear-film break-up time, keratometry, A-scan, and pachymetry on all participants. A confocal microscope Heidelberg HRT3 was used to examine the central cornea and to obtain the mean cell density (cells/mm2). To calculate the proportion of low endothelial cell density, descriptive statistics were used, whereas correlates of endothelial cell density were assessed, using linear regression analyses.

RESULTS

We evaluated a total of 798 eyes of 404 participants aged between 18 and 90 years (males = 187, females = 217). The average endothelial cell density was 2763.6 cells/mm2, and there was a decrease in endothelial cell density with increasing age, irrespective of gender. There was no significant difference in endothelial cell density between males and females. Increasing age (adjusted coefficient - 10.1, p < 0.001), history of smoking (adjusted coefficient - 439.6, p = 0.004), history of ocular surgery (adjusted coefficient - 168.0, p = 0.023), having dry eye (adjusted coefficient - 136.0, p = 0.051), and having arcus senilis (adjusted coefficient - 132.0, p = 0.08), were correlated with lower endothelial cell density. However, increasing corneal diameter (adjusted coefficient 134.0, p = 0.006), increasing central corneal thickness (adjusted coefficient 1.2, p = 0.058), and increasing axial length (adjusted coefficient 65.8, p = 0.026), were correlated with higher endothelial cell density. We found five eyes (0.63%) from different participants with a low endothelial cell density (< 1000cells/mm2).

CONCLUSION

Our study established baseline normal ranges of ECD in a predominantly black African population, and found that low ECD is rare in our population. The elderly, smokers, and those with past ocular surgery are the most vulnerable. The low prevalence could be due to a lack of reference values for the black African population.

Corneal endothelial changes seven years after phacoemulsification cataract surgery

PURPOSE

To evaluate long-term postoperative corneal changes after phacoemulsification cataract surgery.

METHODS

Twenty patients who participated in a previous study regarding corneal endothelial changes after phacoemulsification cataract surgery were examined after 7 years. The patients were divided in three groups based on their initial increase in central corneal thickness day one after the surgery: < 5% increase, 6-20% increase and ≥ 20% increase. The primary outcome measures were corneal endothelial cell loss (ECL), endothelial cell count (ECC) and endothelial morphology.

RESULTS

After 7 years, a difference in cell loss between the groups was observed, except for groups 1 and 2. Endothelial cell count (ECC) differed significantly between groups 1 and 3 at 3 months. At 7 years, there was no difference in ECC between the three groups. Cell loss was found exclusively in group 1 between 3 months and 7 years. Endothelial cell morphology showed a converging pattern between 3 months and 7 years.

CONCLUSION

After phacoemulsification cataract surgery, long-term ECC and morphology appear to converge towards a comparable steady state regardless of initial corneal swelling and endothelial cell loss.

Narrative review after post-hoc trial analysis of factors that predict corneal endothelial cell loss after phacoemulsification: Tips for improving cataract surgery research

PURPOSE

Identifying pre/perioperative factors that predict corneal endothelial-cell loss (ECL) after phacoemulsification may reveal ways to reduce ECL. Our literature analysis showed that 37 studies have investigated one or several such factors but all have significant limitations. Therefore, the data of a large randomized controlled trial (PERCEPOLIS) were subjected to post-hoc multivariate analysis determining the ability of nine pre/perioperative variables to predict ECL.

METHODS

PERCEPOLIS was conducted in 2015-2016 to compare two phacoemulsification techniques (subluxation and divide-and-conquer) in terms of 3-month ECL. Non-inferiority between the techniques was found. In the present study, post-hoc univariate and multivariate analyses were conducted to determine associations between ECL and age, sex, cataract density, preoperative endothelial-cell density, phacoemulsification technique, effective phaco time (EPT), and 2-hour central-corneal thickness. The data are presented in the context of a narrative review of the literature.

RESULTS

Three-month data were available for 275 patients (94% of the randomized cohort; mean age, 74 years; 58% women). Mean LOCSIII cataract grade was 3.2. Mean EPT was 6 seconds. Mean ECL was 13%. Only an older age (beta = 0.2%, p = 0.049) and higher EPT (beta = 1.2%, p = 0.0002) predicted 3-month ECL. Cataract density was significant on univariate (p = 0.04) but not multivariate analysis. The other variables did not associate with ECL.

CONCLUSIONS

Older age may amplify ECL due to increased endothelial cell fragility. EPT may promote ECL via cataract density-dependent and -independent mechanisms that should be considered in future phacoemulsification research aiming to reduce ECL. Our literature analysis showed that the average ECL for relatively unselected consecutively-sampled cohorts is 12%.

The outcomes of postoperative eye patching after cataract surgery in patients with Fuchs' endothelial corneal dystrophy

PURPOSE

To investigate the influence of post-operative eye patching on corneal thickness, endothelial cells' loss and visual acuity in patients diagnosed Fuchs' endothelial corneal dystrophy (FECD).

SETTING

Public healthcare centre, Shamir Medical Centre, Israel.

METHODS

This randomized controlled trial included patients with FECD undergoing routine cataract surgery in a public medical centre. Patients were randomly assigned to 2 groups: the eye undergoing surgery was covered with a patch for 24 h in the first group (patched group), and a plastic shield was used in the second (non-patched group). Both groups received a unique dose of a local steroid and antibiotic post-operatively. The eyes were examined pre-operatively, and on days 1, 7 and 30 post-surgery . Examination included: best corrected visual acuity (BCVA), comeplete slit lamp examination, intra ocular pressure (IOP), anterior chamber depth (ACD), central corneal thickness (CCT) using the IOL Master 700 (Zeiss, Germany) and endothelial cell density (ECD) using Specular microscopy. Cumulative dissipated energy (CDE) and operation time were recorded for all cases.

RESULTS

The study included 46 eyes of 46 patients diagnosed with FECD. Twenty-three eyes in the patched group, and 23 eyes in the non-patched group . Thirty days post-operatively the CCT in the patched group decreased by 60 ± 38 mµ (9%) compared to 92 ± 80 mµ (13.5%) in the non- patched group (p = 0.04). Seven days post-operatively the CCT in the patched group decreased by 31 ± 35 mµ (5%) compared to 58 ± 76 (8%) in the non-patched group, but this difference did not reach statistical significance (p = 0.081). There was no statistically significant difference in endothelial cells loss as well as BCVA at 1, 7 and 30 days post-operatively between the study groups.

CONCLUSIONS

Avoiding eye patch post-operatively after cataract surgery in patients with FECD results in better corneal clarity recovery and reduced corneal edema one month post-operatively. Visual acuity and endothelial cell's loss were not influenced by patching.

Risk factors for corneal endothelial cell loss after phacoemulsification

PURPOSE

The purpose of this study was to evaluate the changes in corneal endothelial cell density (CECD) occurring after cataract phacoemulsification surgery and identify factors associated with cell loss.

MATERIALS AND METHODS

This was a retrospective study involving patients who underwent cataract phacoemulsification surgery between January 1, 2018, and December 31, 2018, at two private hospitals. Demographic data and biometric parameters were obtained preoperatively. Ultrasound metrics were recorded for each operation, including total on time (TOT), total equivalent power in position 3, and cumulative dissipated energy (CDE). Using corneal specular microscopy, CECD was measured preoperatively and postoperatively at 12, 24, and 36 months. Factors associated with decreased CECD were identified.

RESULTS

This study included 223 eyes of 133 patients. The mean CECD was 2530.03 ± 285.42 cells/mm2 preoperatively and significantly decreased to 2364.22 ± 386.98 cells/mm2 at 12 months (P < 0.001), 2292.32 ± 319.72 cells/mm2 at 24 months (P < 0.001), and 2242.85 ± 363.65 cells/mm2 at 36 months (P < 0.001). The amount of cell loss was associated with age, gender, preoperative CECD, preoperative anterior chamber depth, lens thickness, TOT, and CDE. Using multivariate analysis, age, preoperative CECD, and TOT were identified as independent predictors for CECD loss 12 months after surgery.

CONCLUSION

The greatest decrease in CECD occurred during the first year after cataract surgery, and the amount of cell loss was influenced by both baseline patient characteristics and ultrasound metrics. Longer-term prospective studies in a larger cohort may yield more information.

Corneal Edema after Cataract Surgery

This systematic review investigates the prevalence and underlying causes of corneal edema following cataract surgery employing manual phacoemulsification. A comprehensive search encompassing databases such as PubMed, Embase, ProQuest, Cochrane Library, and Scopus was conducted, focusing on variables encompassing cataract surgery and corneal edema. Two independent reviewers systematically extracted pertinent data from 103 articles, consisting of 62 theoretical studies and 41 clinical trials. These studies delved into various aspects related to corneal edema after cataract surgery, including endothelial cell loss, pachymetry measurements, visual performance, surgical techniques, supplies, medications, and assessments of endothelial and epithelial barriers. This review, encompassing an extensive analysis of 3060 records, revealed significant correlations between corneal edema and endothelial cell loss during phacoemulsification surgery. Factors such as patient age, cataract grade, and mechanical stress were identified as contributors to endothelial cell loss. Furthermore, pachymetry and optical coherence tomography emerged as valuable diagnostic tools for assessing corneal edema. In conclusion, this systematic review underscores the link between corneal edema and endothelial cell loss in manual phacoemulsification cataract surgery. It highlights the relevance of factors like patient demographics and diagnostic modalities. However, further research is essential to unravel the complexities of refractive changes and the underlying mechanisms.

Clinical observation of phacoemulsification under the low perfusion pattern and low negative pressure in patients with low corneal endothelial cell density

BACKGROUND

To observe the safety and effect of phacoemulsification combined with intraocular lens (IOL) implantation in patients with low corneal endothelial cell density (CD) under the low perfusion pattern with low negative pressure.

METHODS

In this retrospective case series study, a total of 16 patients (17 eyes) were studied. They had all been diagnosed with low corneal endothelial (CD) and cataracts in the First Affiliated Hospital of Fujian Medical University from December 2019 to October 2021. They underwent phacoemulsification combined with IOL implantation under the low perfusion pattern with low negative pressure. The variations of corneal endothelial( CD), coefficient of variation (CV) of the cell area, central corneal thickness (CCT), visual acuity, and intraocular pressure before and after the operation were observed and assessed. Then a paired t-test, repeated measures analysis of variance, and Pearson correlation analysis were adopted for data analysis.

RESULTS

The mean intraocular pressure of the 17 eyes was 16.88 ± 6.47 mmHg before the operation and 14.41 ± 3.10 mmHg after the operation, showing a statistically significant difference of t = 2.222, and p = 0.041. Before the operation, the mean visual acuity was 0.16 ± 0.09, and after the operation, it was 0.45 ± 0.16, displaying a statistically significant difference of t = -9.917, p < 0.001. Before and after the operation, four of the 17 eyes had no detectable CD. The mean CD of the other 13 eyes at one month after the operation (644.308 ± 106.24 cells/mm²) was lower than that before the operation (709.62 ± 119.19 cells/mm²), and the differences were statistically significant (F = 20.044, p < 0.001). However, no statistically significant differences were found in the mean CV before the operation (31.23 ± 4.21), and at one month after the operation (32.62 ± 3.80; F = 2.130, p = 0.157). Moreover, the mean CCT of 14 eyes at one month after the operation (562.72 ± 27.82 μm) was larger than that before the operation (534.79 ± 24.69 μm).

CONCLUSIONS

The low perfusion pattern with low negative pressure is safe and effective for corneal endothelial dysfunction patients complicated with cataracts.

Application of the Active-Fluidics System in Phacoemulsification: A Review

The fluidics system is an indispensable and primary component of phacoemulsification. Both the gravity-fluidics system and active-fluidics system are commonly used in practice. The irrigation pressure of the gravity-fluidics system is determined by the bottle height, which is relatively constant, while the active-fluidics system is paired with a cassette that contains pressure sensors to monitor intraocular pressure changes. The active-fluidics system allows surgeons to preset a target intraocular pressure value, and it replenishes the fluids proactively; thus, the intraocular pressure is consistently maintained near the target value. Under such circumstances, stable intraocular pressure and anterior chamber volume values could be acquired. Research on surgical safety, efficiency and results have reported several strengths of the active-fluidics system. It is also advantageous in some complicated cataract surgeries. However, the system is not widely used at present, mainly due to its low penetration rate and high equipment cost. Some of its updates such as the new Active Sentry handpiece showed potential superiority in laboratory studies recently, but there is still further research to be conducted. This article gives an overview of the mechanism and performance of the active-fluidics system, and it is expected to provide clues for future research.

The Pathomechanism, Antioxidant Biomarkers, and Treatment of Oxidative Stress-Related Eye Diseases

Oxidative stress is an important pathomechanism found in numerous ocular degenerative diseases. To provide a better understanding of the mechanism and treatment of oxidant/antioxidant imbalance-induced ocular diseases, this article summarizes and provides updates on the relevant research. We review the oxidative damage (e.g., lipid peroxidation, DNA lesions, autophagy, and apoptosis) that occurs in different areas of the eye (e.g., cornea, anterior chamber, lens, retina, and optic nerve). We then introduce the antioxidant mechanisms present in the eye, as well as the ocular diseases that occur as a result of antioxidant imbalances (e.g., keratoconus, cataracts, age-related macular degeneration, and glaucoma), the relevant antioxidant biomarkers, and the potential of predictive diagnostics. Finally, we discuss natural antioxidant therapies for oxidative stress-related ocular diseases.

Cataract surgery and intraocular lens placement in patients with Fuchs corneal dystrophy: a review of the current literature

PURPOSE OF REVIEW

Late-onset Fuchs endothelial corneal dystrophy (FECD) is seen in approximately 4% of individuals over the age of 40. With the growing population of adults over the age of 65, ophthalmologists need to be aware of the preoperative, perioperative, and postoperative considerations involved in cataract surgery in Fuchs patients.

RECENT FINDINGS

Management of cataract patients with FECD requires preoperative assessment of endothelial cell size, density, and morphology. Considerations for perioperative endothelial cell loss include patients with hyperopia and shallow anterior chambers, phacoemulsification technique, transfer of ultrasonic energy to the cornea, corneal-protective perioperative agents, as well as thermal and mechanical damage.

SUMMARY

Ophthalmologists performing cataract surgery on patients with FECD must carefully consider the risks of endothelial cell loss during surgery and minimize the risk of corneal decompensation after surgery. Preoperative management should evaluate the severity of the FECD as well as individual factors such as cataract density, the health and thickness of the cornea, and the anterior chamber depth. Perioperative techniques, adjustments to biometry calculations, and intraocular lens (IOL) selection may help optimize visual outcomes and recovery time.

Utilization rate and usage patterns of phakic and pseudophakic donor corneas recovered by the Singapore Eye Bank

PURPOSE

To compare the utilization rate and usage patterns of pseudophakic and phakic donor corneas recovered by the Singapore Eye Bank.

METHODS

Records of local donor corneas recovered by the Singapore Eye Bank from 2012 to 2017 were examined. Corneas that were deemed suitable for clinical use were stratified into phakic and pseudophakic groups. We examined the basic demographic pattern of both groups and the initial type of surgery/ies that the corneas were suitable for based on tissue parameters such as time from harvesting, stromal clarity, the clear central corneal area, the presence of Descemet's membrane tears or defects, and endothelial cell density and quality. We also identified the types of corneal grafts that the corneas were eventually used for; Penetrating Keratoplasty (PK), Anterior Lamellar Keratoplasty (ALK), Endothelial Keratoplasty (EK). Finally, the overall utilization rates for each group were determined.

RESULTS

A total of 986 corneas deemed suitable for transplant were analyzed, 908 (92%) were phakic and 78 were pseudophakic (8%). The average age of pseudophakic donor corneas was (65 ± 8 yrs. old) and there was a slight male preponderance for both groups (55%). Age adjusted analysis of pseudophakic corneas showed the endothelial cell density (ECD) (mean: 2327 ± 47.1 cells/mm2) and clear area (mean: 7.0 ± 0.7 mm) were lesser than phakic corneas. The percentage of pseudophakic corneas that were of EK standard (ECD >2500 cells/mm2) were lower compared to phakic corneas (37% and 77% respectively, p < 0.001). There was significant correlation between previous cataract surgery and the endothelial cell count of the donor corneas (p < 0.001), and regression analysis also showed a strong association of ECD with cataract surgery in reference to non-cataract surgery (-478.8 (95% CI-576.9 to -380.7). The overall utilization rate for pseudophakic corneas was 58% compared to that of phakic corneas at 83%. The most common reason for pseudophakic corneas not to be utilized was due to the presence of Descemet's membrane (DM) tears or defects under the main or side port incision created during phacoemulsification (30%). Phakic corneas were used primarily for optical grafts 84% (mainly EK) while pseudophakic corneas were used mostly for therapeutic/tectonic grafts 47% (mainly ALK or patch grafts).

CONCLUSION

Compared to phakic donor corneas, pseudophakic corneas generally have lower overall tissue quality leading to lower uptake by surgeons and lower utilization rates. Eye banks must continuously refine their donor acceptance criteria and engage surgeons to optimize utilization of each recovered tissue.

Ascorbic acid ameliorates corneal endothelial dysfunction and enhances cell proliferation via the noncanonical GLUT1-ERK axis

BACKGROUND

The pumping function of corneal endothelial cells (CECs) plays a pivotal role in the maintenance of corneal water homeostasis. Corneal endothelial dysfunction (CED) leads to corneal edema and opacity, but with the exception of keratoplasty, no optimal therapeutic strategies have been established for CED. In this study, we aimed to investigate the ameliorative effect of ascorbic acid (AA) on CED and the underlying mechanism of action in the corneal endothelium.

METHODS

Rabbit corneal endothelial damage was induced by anterior chamber injection of benzalkonium chloride (BAK). AA was topically administered to the corneal surface, and the transparency and thickness of the cornea were assessed by external eye photography, slit-lamp photography, and ultrasonic pachymetry. To further analyze the mechanism, rabbit CECs and immortalized human CECs (B4G12 cells) were cultured. A ferric reducing/antioxidant and AA (FRASC) assay was performed to measure the AA concentration. Cell proliferation was evaluated by cell counting and bromodeoxyuridine (BrdU) labeling assays, and protein expression was examined by liquid chromatography-mass spectrometry (LC/MS) and immunoblotting. The involvement of glucose transporter 1 (GLUT1) and phospho-ERK was evaluated via GLUT1-siRNA and phospho-ERK inhibitor (PD98059) treatment.

INTERPRETATION

We observed that topical AA ameliorates BAK-induced rabbit corneal endothelial damage. Furthermore, we demonstrated that AA is transported into B4G12 cells via GLUT1, and afterward, AA increases ERK phosphorylation and promotes cell proliferation. Our findings indicate that CEC proliferation stimulated via the noncanonical AA-GLUT1-ERK axis contributes to AA-enhanced healing of CED.

Accelerated Corneal Endothelial Cell Loss after Phacoemulsification in Patients with Mildly Low Endothelial Cell Density

By evaluating preoperative endothelial cell density (ECD), ECD loss after phacoemulsification can be predicted. In this retrospective cross-sectional study, we compared outcomes of phacoemulsification with different levels of preoperative ECD. Three-hundred-and-fifty-three patients aged between 18 and 90 years received phacoemulsification at Chang Gung Memorial Hospital. Age (p = 0.003), preoperative logMAR (p = 0.048), cataract grade (p = 0.005), preoperative ECD (p < 0.001), operation time (p = 0.043), phacoemulsification time (p = 0.001), and phacoemulsification energy (p < 0.001) were significantly associated with postoperative ECD change (%). Patients were divided into three groups according to preoperative ECD levels. Level of ECD, coefficient of variation (CV), cell hexagonality (HEX), central corneal thickness (CCT), visual acuity, underlying diseases, and complications were analyzed. With regard to groups, 29, 71, and 252 patients were respectively allocated into the markedly low (group A; ECD below 1000 cells/mm²), mildly low (group B; ECD between 1000 to 2000 cells/mm²), and normal (group C; ECD above 2000 cells/mm²) ECD level groups. The highest CV (40.8 ± 13.9%; p < 0.001) and lowest HEX (58.4 ± 14.6%; p < 0.001) were found in group A. Significant ECD loss was found in group B (28.9 ± 9.2%) as compared to group A (19.9 ± 5.4%) and C (15.0 ± 12.0%) (p < 0.001). No significant differences were found with regard to changes in CV (p = 0.941), HEX (p = 0.937), CCT (p = 0.346), and logMAR (p = 0.557) among the three groups. In conclusion, preoperative ECD level could be a novel predictive value for postoperative cell loss, which was the most prominent in mildly low ECD level group. Less phacoemulsification energy, earlier surgical intervention, or novel topical medications could be suggested for patients with an ECD range from 1000 to 2000 cells/mm².

Comparing corneal outcome between femtosecond laser-assisted cataract surgery and conventional phaco surgery in Fuchs' endothelial dystrophy patients: a randomized pilot study with 6mo follow up

AIM

To compare the corneal outcome in Fuchs' endothelial dystrophy (FED) patients between femtosecond laser-assisted cataract surgery (FLACS) and conventional phaco surgery (CPS).

METHODS

This was a randomized controlled study comparing one eye surgery by FLACS and the contralateral eye operated by CPS (stop and chop technique) in FED patients. Central corneal thickness, corneal light backscatter, corneal densitometry, and central corneal endothelial cell count and hexagonality (noncontact endothelial cell microscope), and corrected distance visual acuity (CDVA) were assessed preoperatively and at day 1, 40, and 180 postoperatively.

RESULTS

Totally 31 patients (16 women) were included. At day 40 postoperatively, the mean endothelial cell loss (ECL) was 23.67% by FLACS and 17.30% by CPS (P=0.53). At day 180 postoperatively, ECL was 25.58% in FLACS and 21.32% in CPS (P=0.69). Densitometry data in all layers and all annuli from anterior layer to posterior layer in annuli 0-2, 2-6, 6-10 and 10-12, total densitometry with all layers and all annuli was performed. A significant difference was found in 6-10 (posterior layer) at day 1 with -1.42 grayscale units (GSU; 95%CI: -2.66 to -0.19, P=0.02). In 10-12 (anterior layer, central layer and all layers) at day 40 were significant different with 7.7 (95%CI: 1.89 to 13.50, P=0.009), 3.97 (95%CI: 0.23 to 7.71, P=0.03), 4.73 GSU (95%CI: 0.71 to 8.75, P=0.02), respectively. In the remaining parameters we found no difference between the two groups (P>0.05). Three CPS eyes suffered from corneal decompensation.

CONCLUSION

There is no significant difference in corneal outcome between FLACS and CPS. Endothelial cell density and pentacam corneal outcome may be inadequate as outcome parameters in FED patients.

Accelerated corneal endothelial cell loss in two patients with granulomatosis with polyangiitis following phacoemulsification

BACKGROUND

Generally, the loss rate of human endothelial cells (HCEC) in routine cataract surgery is 8.5%. When the corneal endothelial cells density (ECD) drops, the HCEC may decompensate to keep cornea dehydration which leads to corneal edema. Granulomatosis with polyangiitis (GPA) is an uncommon autoimmune disease involving multiple organs including eyes such as conjunctivitis, scleritis, uveitis, and corneal ulcer. In this study, we report two cases of GPA whose corneal ECD decreased significantly after phacoemulsification cataract surgery.

CASE PRESENTATION

In the first case of 69-year-old male with GPA, the ECD dropped 39.6% (OD) four months after phacoemulsification and 38.1% (OS) six months postoperatively respectively. At the final follow-up, the residual ECD was only 55% in the right eye in the 49th month, and 56% remained in the left eye in the 39th month. In the second case of 54-year old female, left ECD dropped 63.9% at the 4th month after surgery and 69.6% ECD remained at the 15th month postoperatively while similar ECD of right eye before and after left eye surgery.

CONCLUSION

Extensive preoperative ophthalmic evaluation and meticulous postoperative inflammation control should be applied to prevent severe loss of HCEC in GPA patients.

Corneal Endothelial Cell Loss after Phacoemulsification in Eyes with a Prior Acute Angle-closure Attack

Purpose

To evaluate endothelial damage after cataract surgery in eyes affected by an angle-closure attack (ACA) and compare it to that in the unaffected fellow eyes (FEs) of patients with ACA and normal eyes (NEs).

Methods

The medical data of eyes affected by ACA, FEs (with no history of acute glaucoma attack), and NEs of patients who underwent cataract surgery with simultaneous intraocular lens implantation were retrospectively reviewed. Endothelial cell density (ECD) and central corneal thickness (CCT) measured before surgery and at 1 week, 1 month, and 3 months after surgery were analyzed, and the percentages of loss in ECD and increase in CCT of the three groups were compared.

Results

The study enrolled 140 eyes from 100 patients (50 eyes in the ACA group, 40 eyes in the FE group, and 50 eyes in the NE group). The mean ECD was significantly lower in the ACA group than in the other groups (p < 0.001). However, the percentage of ECD reduction was not significantly greater in the ACA group than in the other groups (p > 0.05). None of the eyes developed corneal edema at 3 months postoperatively. Moreover, the CCTs of the three groups were similar throughout the follow-up period (p > 0.05).

Conclusions

Phacoemulsification was not associated with greater endothelial cell loss in the ACA group than in the NE and FE groups. This finding shows that ACA history may not contribute to the exacerbation of corneal endothelial damage in cataract surgery.

Comparison of Endothelial Cell Density, Morphological Changes and Central Corneal Thickness after Phacoemulsification between Diabetic and Non-Diabetic Patients

Background:

Corneal endothelial tissues are susceptible to mechanical trauma from ultrasound energy during phacoemulsification. Several studies have reported various results of phacoemulsification effect on corneal endothelial cells between diabetic and non-diabetic patients.

Purpose:

To compare endothelial density, hexagonality, Coefficient of Variance (CV) and Central Corneal Thickness (CCT) changes between diabetic and non-diabetic patients at four weeks after phacoemulsification.

Methods:

Specular microscopy examinations prior to phacoemulsification and at four-weeks after phacoemulsification were performed on diabetic and non-diabetic groups with cataract. Later, patients in the diabetic group were divided based on their HbA1c level. The changes in endothelial density, the percentage of hexagonality, CV and CCT were evaluated.

Results:

At a four-weeks follow up, there were no statistical differences in endothelial cells density, CV and CCT changes between diabetic and non-diabetic groups. Mean (SD) of hexagonality percentage at four weeks of follow-up was lower (p-value=0.001) in diabetic group [(14.6) 41.7%] compared to non-diabetic group [(14.5) 50.1%]. There were no differences in endothelial cells density, hexagonality, CV and CCT values between the diabetic group with HbA1c level <7.5% and HbA1c level ≥7.5% at 4-weeks after phacoemulsification.

Conclusion:

There were no statistically significant differences in the endothelial loss, reduction of CV and CCT changes between the diabetic and non-diabetic group at four-weeks follow up after phacoemulsification. Diabetic group showed greater hexagonality decrease compared to non-diabetic group at four weeks after phacoemulsification. Different HbA1c levels did not affect the changes in endothelial density, the percentage of hexagonality, CV and CCT after phacoemulsification.

Topical Ascorbic Acid Ameliorates Oxidative Stress-Induced Corneal Endothelial Damage via Suppression of Apoptosis and Autophagic Flux Blockage

Compromised pumping function of the corneal endothelium, due to loss of endothelial cells, results in corneal edema and subsequent visual problems. Clinically and experimentally, oxidative stress may cause corneal endothelial decompensation after phacoemulsification. Additionally, in vitro and animal studies have demonstrated the protective effects of intraoperative infusion of ascorbic acid (AA). Here, we established a paraquat-induced cell damage model, in which paraquat induced reactive oxygen species (ROS) production and apoptosis in the B4G12 and ARPE-19 cell lines. We demonstrate that oxidative stress triggered autophagic flux blockage in corneal endothelial cells and that addition of AA ameliorated such oxidative damage. We also demonstrate the downregulation of Akt phosphorylation in response to oxidative stress. Pretreatment with ascorbic acid reduced the downregulation of Akt phosphorylation, while inhibition of the PI3K/Akt pathway attenuated the protective effects of AA. Further, we establish an in vivo rabbit model of corneal endothelial damage, in which an intracameral infusion of paraquat caused corneal opacity. Administration of AA via topical application increased its concentration in the corneal stroma and reduced oxidative stress in the corneal endothelium, thereby promoting corneal clarity. Our findings indicate a perioperative strategy of topical AA administration to prevent oxidative stress-induced damage, particularly for those with vulnerable corneal endothelia.

Risk factors for endothelial cell damage in diabetics after phacoemulsification

BACKGROUND

To assess the corneal endothelium, central corneal thickness and the factors associated with endothelial cell damage after phacoemulsification in diabetics in comparison with non-diabetics.

METHODS

It was a case control study with 80 eyes each in the diabetic group and the control group. Intraoperative mydriasis, effective phaco time (EPT) and postoperative inflammation were measured. Preoperative, 1^st week, 6^th week and 3^rd month postoperative endothelial cell density (ECD), coefficient of variation (CV), hexagonality and central corneal thickness (CCT) were also measured using Konan noncon robo specular microscope (Model - NSP 9900).

RESULTS

In the control group, patients in the age group of 60-69 years were 3.8 times more at risk of ECL compared to patients in the age group of 50-59 years. Patients in whom EPT was ≥0.50 min, were 8.8 times more at risk of ECL when compared to patients in whom EPT <0.25 min. In the diabetic group, patients who had an inflammatory score of 1+ in the first postoperative week; also had 5.7 times more risk of ECL when compared to patients in whom the inflammatory score was 0.5+ in the first postoperative week. There was a significant increase in CV (p-0.03) and CCT (p-0.03), significant decrease in the hexagonality (p-0.01) and no statistically significant difference in the endothelial cell loss (ECL) (p-0.34) in diabetics after phacoemulsification when compared to controls.

CONCLUSION

The present study reveals postoperative inflammation as a risk factor for ECL in diabetics and not intraoperative mydriasis and EPT.

Comparison of changes in corneal endothelial cell density and central corneal thickness between conventional and femtosecond laser-assisted cataract surgery: a randomised, controlled clinical trial

BACKGROUND/AIM

To identify changes in endothelial cell density (ECD) and central corneal thickness (CCT) in eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) compared with conventional phacoemulsification surgery (CPS).

METHODS

This is an intraindividual randomised, controlled clinical trial. One eye was randomised to receive FLACS, while the contralateral eye of the same patient received CPS. The femtosecond laser pretreatment included creating main and side-port corneal incisions, capsulotomy and lens fragmentation. Non-contact endothelial cell microscopy and pachymetry were performed preoperatively and at postoperative day 1, week 1, month 1 and month 3.

RESULTS

A total of 134 paired eyes from 67 patients were included in the analysis. ECD was not significantly different between the two groups at either postoperative month 1 (2370±580 cells/mm² and 2467±564 cells/mm² in FLACS and CPS groups, respectively; p=0.18) or at postoperative month 3 (2374±527 cells/mm² and 2433±526 cells/mm² in FLACS and CPS groups, respectively; p=0.19). No significant difference was observed in the mean CCT values between the two groups over the follow-up period (p>0.05).

CONCLUSION

Postoperative corneal ECD and CCT were comparable between FLACS and CPS during the 3 months' follow-up period.

Immune privilege in corneal transplantation

Corneal transplantation is the most successful solid organ transplantation performed in humans. The extraordinary success of orthotopic corneal allografts, in both humans and experimental animals, is related to the phenomenon of "immune privilege". Inflammation is self-regulated to preserve ocular functions because the eye has immune privilege. At present, three major mechanisms are considered to provide immune privilege in corneal transplantation: 1) anatomical, cellular, and molecular barriers in the cornea; 2) tolerance related to anterior chamber-associated immune deviation and regulatory T cells; and 3) an immunosuppressive intraocular microenvironment. This review describes the mechanisms of immune privilege that have been elucidated from animal models of ocular inflammation, especially those involving corneal transplantation, and its relevance for the clinic. An update on molecular, cellular, and neural interactions in local and systemic immune regulation is provided. Therapeutic strategies for restoring immune privilege are also discussed.

Perioperative topical ascorbic acid for the prevention of phacoemulsification-related corneal endothelial damage: Two case reports and review of literature

BACKGROUND

The current case report describes successful phacoemulsification with the aid of perioperative topical ascorbic acid (AA) in two patients with corneal endothelial disorders to prevent postoperative corneal endothelial decompensation.

CASE SUMMARY

Two eyes of two patients underwent phacoemulsification with pre-existing corneal endothelial disorders including Fuchs corneal endothelial dystrophy (Patient 1) and endotheliitis (Patient 2). Topical AA was applied to both patients at least one month before and after with a frequency of four times per day. After the surgery, both eyes improved best-corrected visual acuity (BCVA) and there was limited human corneal endothelial cell loss without signs of corneal endothelial decompensation, such as deteriorated BCVA or persistent corneal edema during the follow-up of at least two years.

CONCLUSION

Perioperative administration of topical AA may be an alternative therapy to the triple procedure in patients expecting to undergo cataract surgery.

Changes in corneal endothelial density following scleral buckling surgery for rhegmatogenous retinal detachment: a retrospective cross-sectional study

BACKGROUND

To investigate the effect of scleral buckling (SB) on the morphology and density of human corneal endothelial cells (HCEC).

METHODS

In this retrospective cross-sectional study, 26 patients who had undergone SB due to rhegmatogenous retinal detachment were enrolled, in which 15 patients received encircling while the other 11 segment types of SB. The postoperative status of affected eye, preoperative status of affected eye, and the contralateral healthy eye was served as the study, control and contralateral groups. The images of the corneal endothelium was obtained by specular microscopy at least three months postoperatively and analyzed.

RESULTS

Postoperative best-corrected visual acuity of the study group was worse than that of another two groups (P < 0.001) while intraocular pressure and biometry data were similar. The mean cell area and standard deviation were larger in the study group while the coefficient of variation revealed no difference. The study group manifested a lower endothelial cell density than that of the control and the contralateral (P < 0.001) groups. Concerning the percentage of hexagonal cells, the study group showed a lower hexagonality than the control group (P = 0.04). No difference of the endothelial morphology was found between the segmental subgroup and the encircling subgroup, nor was a significant difference about endothelial cell loss found in the study group with different measurement interval.

CONCLUSIONS

Scleral buckling leads to short-term decreased endothelial cell density and hexagonality, while the rest of morphological features remain unchanged. Moreover, both the segmental and encircling SB procedures yield similar postoperative HCEC status.

Effects of anterior chamber depth and axial length on corneal endothelial cell density after phacoemulsification

Objective:

To evaluate mean decrease in Corneal Endothelial cell Density (CED) after phacoemulsification in patients with different Anterior Chamber Depths (ACDs) and Axial Lengths (ALs).

Methods:

This prospective stratified controlled study was conducted at PNS Shifa Hospital, Karachi. One hundred eyes of 90 patients, scheduled to undergo phacoemulsification surgery, were included. AL and ACD of each patient were calculated preoperatively using IOL Master. Cataracts were classified according toLens Opacities Classification System III (LOCS III) giving nuclear opalescence (NO) grades on slit lamp examination and only patients with grades NO2 and NO3 were included. Eyes were divided into two groups according to ACD and AL: Group-I: ACD 2.0mm – 3 mm and AL 22mm – 23.5mm; Group-II: ACD 3.1 mm -4.0 mm and AL 23.6mm – 25mm. CED measurements were done preoperatively and 2 month postoperatively using specular microscopy. The difference in CED change (Endothelial Cell Loss) between the two groups after surgery was analyzed using SPSS, v 22; IBM Corporation, Armonk, NY.

Results:

Differences in gender, laterality, age and preoperative CED between two groups were not significant. Difference in postoperative CED was also not significant, however difference in mean change and mean frequency change in CED between two groups was found to be statistically significant.

Conclusion:

ACD and AL affect the CED during phacoemulsification and Intraocular Lens(IOL) implantation and can be considered as risk factors of peroperative endothelial cell loss.

Comparing Outcomes of Phacoemulsification With Femtosecond Laser-Assisted Cataract Surgery in Patients With Fuchs Endothelial Dystrophy

PURPOSE

To compare the outcome in patients with Fuchs endothelial dystrophy (FED) who underwent standard phacoemulsification vs femtosecond laser-assisted cataract surgery (FLACS) in the treatment of visually significant cataracts.

DESIGN

Retrospective, comparative, interventional case series.

METHODS

Patient or Study Population: Between April 2013 and December 2016, 140 FED eyes with cataracts of all densities were included. Seventy-two eyes underwent phacoemulsification and 68 eyes underwent FLACS. Intervention or Observation Procedures: Automated noncontact specular microscopy was performed at baseline and postoperatively over a mean of 17.91 ± 10.47 months. Parameters collected include visual acuity, slit-lamp examination findings, and intraoperative findings.

MAIN OUTCOME MEASURES

Pachymetry, endothelial cell density (ECD), and coefficient of variance (COV) were compared.

RESULTS

Phacoemulsification had significantly greater postoperative median loss of ECD of 229.0 cells/mm² (14.2%) compared to FLACS ECD of 133.0 cells/mm² (6.5%) (U = 1343.0, Z = -2.241, P = .025). Mean loss of ECD was 346.524 ± 420.472 cells/mm² and 119.964 ± 434.882 cells/mm² for phacoemulsification and FLACS, respectively (P = .005). Mean percentage loss of ECD was 15.3% ± 17.5% for phacoemulsification and 4.4% ± 25.0% for FLACS (P = .006). Eyes that underwent phacoemulsification had 10.7% ± 15.4% mean ECD loss in the mild cataract group, and in the moderate/hard cataract group 19.5% ± 18.0%, P = .045. Eyes that underwent FLACS had 0.9% ± 22.5% mean ECD loss in the mild cataract group, and 8.2% ± 26.3% in the moderate/hard cataract group, P = .291. Comparison between procedures of mean ECD loss for moderate/hard cataracts was significant (P = .043).

CONCLUSIONS

FLACS is shown to be superior to phacoemulsification in reducing postoperative endothelial cell loss in FED patients, which translates to a lower risk of corneal decompensation, especially in patients with moderate/hard cataract densities.

Outcomes of conventional phacoemulsification versus femtosecond laser-assisted cataract surgery in eyes with Fuchs endothelial corneal dystrophy

PURPOSE

To compare the outcomes in eyes with Fuchs endothelial corneal dystrophy after standard phacoemulsification with those of femtosecond laser-assisted cataract surgery.

SETTING

Bascom Palmer Eye Institute, Miami, Florida, USA.

DESIGN

Retrospective case series.

METHODS

Charts from patients diagnosed with Fuchs endothelial corneal dystrophy who had phacoemulsification cataract surgery at Bascom Palmer Eye Institute between January 1, 2014, and January 1, 2017, were reviewed. The Institutional Review Board, University of Miami Human Subjects Research Office, approved the study protocol. Complicated surgeries and cases with concurrent keratoplasty, previous keratoplasty or glaucoma surgery, or a follow-up shorter than 3 months were excluded. The corrected distance visual acuity (CDVA), central corneal thickness (CCT), and corneal edema at each visit were analyzed. Clinically significant corneal decompensation was defined by corneal edema with CDVA worse than 20/50 lasting more than 3 months, any case resulting in keratoplasty, or both.

RESULTS

The study comprised 207 eyes of 207 patients (64 femtosecond laser-assisted cataract surgery, 143 conventional phacoemulsification). Demographics, baseline guttata and cataract grades, and follow-up time (mean 30 months) were similar between groups (P > .05). The proportion of cases progressing to clinically significant decompensation (13%) was similar between groups (P > .05). Univariate Cox survival analysis also found no difference (hazard ratio, 1.0; 95% confidence interval, 0.4-2.7; P = .96).

CONCLUSIONS

Compared with conventional phacoemulsification, femtosecond laser-assisted cataract surgery did not lower the rate of corneal decompensation in eyes with mild to moderate Fuchs endothelial corneal dystrophy.

Changes in corneal thickness and corneal endothelial cell density after phacoemulsification cataract surgery: a double-blind randomized trial

Background

Age-related cataract is a leading cause of visual impairment, considered a global health burden, it is responsible for over 47% of blindness worldwide. Surgical intervention is usually the treatment of choice and phacoemulsification cataract surgery with implantation of an intraocular lens is the most common procedure, which may have several complications.

Objectives

To determine the effects of phacoemulsification surgery on corneal endothelial cell density and corneal thickness in patients undergoing cataract surgery.

Methods

The present study was conducted on patients diagnosed with immature senile cataract requiring surgical intervention from November 2013 to 2014 in Khatam al Anbia Hospital (a tertiary ophthalmology center). Physical examination included best-corrected visual acuity using the Snellen chart, refraction, slit-lamp bio-microscopy for anterior chamber evaluation, keratometry, Goldman tonometry, gonioscopy, and dilated indirect ophthalmoscopy, pachymetry, specular microscopy and biometry. Surgery was performed by similar method and technique in all patients. The change in the corneal endothelial cell count or density and central corneal thickness (CCT) number were compared preoperatively and one day, one week, one month, and three months post–operatively.

Results

A total of 92 eyes of 85 patients (43 females and 42 males with mean age of 62.1±12.2 years) were studied. Patients’ visual acuity improved (log MAR: 1±0.5 preoperatively to 0.45±0.34 post-operatively) (p=0.001). There was 11.4% endothelial cell loss (ECL) and significant decrease in ECC (from 2,791.15±99.86 to 2,472.87±472.14) (p=0.04). The central corneal thickness increased significantly (from 530.47±2.60 to 540.91±36.07). Diabetic patients (12.9%) had a statistically significant higher ECL rate after phacoemulsification (14.6% versus 8.7% respectively, p=0.002).

Conclusion

Phacoemulsification resulted in significant corneal endothelial damage, which is particularly important in patients with a borderline reservoir of endothelial cell, such as diabetic patients, which highlights the necessity of refining the current surgical methods and instruments to minimize the endothelial damage.

Trial registration

The trial was registered in the Thai clinical trial registry (http://www.clinicaltrials.in.th) with the ID: TCTR20171122001.

Funding

The study was supported by a research grant of Mashhad University of Medical Sciences.

Factors associated with graft survival and endothelial cell density after Descemet's stripping automated endothelial keratoplasty

Postoperative endothelial cell loss leads to graft failure after corneal transplantation, and is one of the important issues for long-term prognosis. The objective of this study was to identify clinical factors affecting graft survival and postoperative endothelial cell density (ECD) after Descemet’s stripping automated endothelial keratoplasty (DSAEK). A total of 198 consecutive Japanese patients (225 eyes) who underwent DSAEK were analysed using Cox proportional hazard regression and multiple linear regression models. The candidate factors included recipient age; gender; diagnosis; pre-existing iris damage state, scored based on its severity; the number of previous intraocular surgeries; graft ECD; graft diameter; simultaneous cataract surgery; surgeons experience; intraoperative iris damage; postoperative rebubbling; and graft rejection. Eyes with higher pre-existing iris damage score and more number of previous intraocular surgery had a significantly higher risk of graft failure (HR = 8.53; P < 0.0001, and HR = 2.66; P = 0.026, respectively). Higher pre-existing iris damage score, lower graft ECD, and smaller graft diameter were identified as significant predisposing factors for lower postoperative ECD. The results show that iris damage status before DSAEK may be clinically useful in predicting the postoperative course. Avoiding intraoperative iris damage, especially in eyes with low ECD can change the prognosis of future DSAEK.

Changes in corneal endothelium cell characteristics after cataract surgery with and without use of viscoelastic substances during intraocular lens implantation

PURPOSE

To evaluate whether the use of balanced salt solution (BSS) or an ophthalmic viscoelastic device (OVD) during hydrophilic acrylic intraocular lens (IOL) implantation variously impacts corneal endothelial cell characteristics in eyes undergoing uneventful phacoemulsifications.

METHODS

Prospective nonrandomized observational clinical trial. Patients were assigned either to the BSS plus(®) or to the OVD Z-Celcoat™ group depending on the substance used during IOL implantation. Corneal endothelium cell characteristics were obtained before, 1 week, and 6 weeks after surgery. Intraoperative parameters (eg, surgery time, phacoemulsification energy) were recorded.

RESULTS

Ninety-seven eyes were assigned to the BSS plus and 86 eyes to the Z-Celcoat group. Preoperative corneal endothelium cell density (ECD) and endothelium cell size were 2,506±310 cells/mm(2)/2,433±261 cells/mm(2) and 406±47 µm(2)/416±50 µm(2) (P=0.107/P=0.09). After 1 and 6 weeks, ECD decreased and endothelium cell size increased significantly in both groups (each P<0.001) without significant differences between both groups (each P>0.05). Irrigation-aspiration suction time (30.3±16.6 versus 36.3±14.5 seconds) and overall surgical time (7.2±1.2 versus 8.0±1.4 minutes) were significantly longer in the OVD Z-Celcoat group (each P<0.001). No complications or serious side effects occurred.

CONCLUSION

Implantation of a hydrophilic acrylic IOL under BSS infusion seems to be a useful and faster alternative in experienced hands without generating higher ECD loss rates.

RNA toxicity and missplicing in the common eye disease fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) is an inherited degenerative disease that affects the internal endothelial cell monolayer of the cornea and can result in corneal edema and vision loss in severe cases. FECD affects ∼5% of middle-aged Caucasians in the United States and accounts for >14,000 corneal transplantations annually. Among the several genes and loci associated with FECD, the strongest association is with an intronic (CTG·CAG)_n trinucleotide repeat expansion in the TCF4 gene, which is found in the majority of affected patients. Corneal endothelial cells from FECD patients harbor a poly(CUG)_n RNA that can be visualized as RNA foci containing this condensed RNA and associated proteins. Similar to myotonic dystrophy type 1, the poly(CUG)_n RNA co-localizes with and sequesters the mRNA-splicing factor MBNL1, leading to missplicing of essential MBNL1-regulated mRNAs. Such foci and missplicing are not observed in similar cells from FECD patients who lack the repeat expansion. RNA-Seq splicing data from the corneal endothelia of FECD patients and controls reveal hundreds of differential alternative splicing events. These include events previously characterized in the context of myotonic dystrophy type 1 and epithelial-to-mesenchymal transition, as well as splicing changes in genes related to proposed mechanisms of FECD pathogenesis. We report the first instance of RNA toxicity and missplicing in a common non-neurological/neuromuscular disease associated with a repeat expansion. The FECD patient population with this (CTG·CAG)_n trinucleotide repeat expansion exceeds that of the combined number of patients in all other microsatellite expansion disorders.

Effect of continuous ultrasonic phacoemulsification with anterior chamber maintainer on corneal endothelial damage in hard nuclear cataract

PURPOSE

To study the effects of continuous ultrasonic phacoemulsification performed with and without an anterior chamber maintainer (ACM) on corneal endothelial damage in patients with hard nuclear cataract.

METHODS

Sixty eyes in 60 patients with hard nuclear cataract (grade IV), one lesion per eye, were randomly allocated into 2 groups: continuous ultrasonic phacoemulsification with (group A) or without (group B) ACM. The intraoperative accumulated energy complex parameter (AECP), frequency of shallow anterior chamber, and postoperative corneal incision edema, corneal endothelial cell counts, and visual recovery were compared between the groups.

RESULTS

The intraoperative AECP, postoperative corneal incision edema, and postoperative visual recovery showed no significant differences between the groups (p&gt;0.05). At 1 month postoperatively, the corneal endothelial cell loss rate and hexagonal cell percentage (postoperative compared to preoperative) in groups A and B were 0.117 ± 0.12 and 9.97 ± 9.52% and 0.15 ± 0.73 and 8.5 ± 4.60%, respectively, with no significant difference noted (p&gt;0.05). The endothelial cell mutation rate was significantly lower in group A than in group B at 6.41 ± 6.78% and 28.27 ± 27.95%, respectively (p&lt;0.05). The frequency of intraoperative shallow anterior chamber was significantly lower in group A than in group B (2 vs 17 times, p&lt;0.05).

CONCLUSIONS

Continuous ultrasonic phacoemulsification with ACM is a safe, effective, simple, and easy method to treat hard nuclear cataract and causes minimal damage to corneal endothelial cells. It is an ideal surgical option and is worth popularizing.

Fuchs endothelial corneal dystrophy: clinical characteristics of surgical and nonsurgical patients

PURPOSE

To review the patient and clinical characteristics of patients with Fuchs endothelial corneal dystrophy (FECD).

METHODS

Review of records for every patient who presented to the Bascom Palmer Eye Institute between 2003 and 2009 whose visit was coded for endothelial corneal dystrophy (International Classification of Diseases, Ninth Revision [ICD9] 371.57), bullous keratopathy (ICD9 371.23), or who underwent a corneal surgery with or without cataract extraction. Demographic, clinical, and ancillary testing data were collected from the time of presentation, diagnosis, and follow-up, and the use, timing, and type of surgical interventions was documented, with 6-month and final visual acuities recorded.

RESULTS

A total of 2,370 charts were included in this study, of which 966 patients had a diagnosis of FECD. Of these, 197 patients (21%) received a corneal transplantation procedure. The surgery most often performed was penetrating keratoplasty with or without cataract extraction (66%), followed by endothelial keratoplasty with or without cataract extraction (34%). The risk factors for surgery include worse visual acuity at presentation (20/60 Snellen visual acuity in surgical patients versus 20/40 Snellen visual acuity in nonsurgical patients, P<0.001), greater average central corneal thickness (635 μm versus 592 μm, P<0.001), loss of visual acuity over time (two lines lost versus zero lines lost, P<0.001), increasing age (P<0.001), and male sex (P=0.008). Over half of patients (52%) did not receive surgery despite poor vision.

CONCLUSION

During this time period, FECD did not have a consistent pattern for management or treatment, and despite advances in surgical techniques, most patients were still managed without surgery.

Comprehensive assessment of genetic variants within TCF4 in Fuchs' endothelial corneal dystrophy

PURPOSE

The single nucleotide variant (SNV), rs613872, in the transcription factor 4 (TCF4) gene was previously found to be strongly associated (P = 6 × 10(-26)) with Fuchs' endothelial corneal dystrophy (FECD). Subsequently, an intronic expansion of the repeating trinucleotides, TGC, was found to be even more predictive of disease. We performed comprehensive sequencing of the TCF4 gene region in order to identify the best marker for FECD within TCF4 and to identify other novel variants that may be associated with FECD.

METHODS

Leukocyte DNA was isolated from 68 subjects with FECD and 16 unaffected individuals. A custom capture panel was used to isolate the region surrounding the two previously validated markers of FECD. Sequencing of the TCF4 coding region, introns and flanking sequence, spanning 465 kb was performed at >1000× average coverage using the Illumina HiSequation 2000.

RESULTS

TGC expansion (>50 repeats) was present in 46 (68%) FECD-affected subjects and one (6%) normal subject. A total of 1866 variants, including 1540 SNVs, were identified. Only two previously reported SNVs resided in the TCF4 coding region, neither of which segregated with disease. No variant, including TGC expansion, correlated perfectly with disease status. Trinucleotide repeat expansion was a better predictor of disease than any other variant.

CONCLUSIONS

Complete sequencing of the TCF4 genomic region revealed no single causative variant for FECD. The intronic trinucleotide repeat expansion within TCF4 continues to be more strongly associated with FECD than any other genetic variant.

Descemet's stripping automated endothelial keratoplasty with anterior chamber intraocular lenses: complications and 3-year outcomes

PURPOSE

To describe outcomes and complications following Descemet's stripping automated endothelial keratoplasty (DSAEK) in eyes with pseudophakic bullous keratopathy (BK) while retaining the anterior chamber intraocular lenses (ACIOL).

METHODS

We included consecutive patients who underwent DSAEK for BK at a single tertiary centre from 1 January 2008 to 1 April 2010, from our prospective cohort (Singapore Corneal Transplant Study). We compared eyes with BK, which underwent DSAEK while retaining ACIOL (n=18), to those with DSAEK alone with the posterior chamber intraocular lenses left in place as a comparison group (n=114). Main outcome measures were endothelial cell (EC) loss and graft survival.

RESULTS

The percentage EC loss at 1 year was 31.9±21.3% in the DSAEK with ACIOL group compared to 24.5±21.2% in the DSAEK group (p=0.516); however, this figure was significantly greater in the DSAEK with ACIOL group at 3 years compared to the DSAEK group (55.3±29.2% vs 33.3±20.8%; p=0.01 respectively). Graft survival was also significantly poorer in the DSAEK ACIOL group compared to the DSAEK group over 3 years (log rank p=0.002).

CONCLUSIONS

We found that although eyes with BK and ACIOL that underwent DSAEK while retaining the ACIOL suffered EC loss which was not significantly greater at 1 year, EC loss and graft survival were significantly poorer compared to DSAEK controls at 3 years postoperatively.

Functions of corneal endothelial cells do not change after uptake of superparamagnetic iron oxide nanoparticles

To avoid donor tissue shortages, ex vivo cultured human corneal endothelial cell (HCEC) transplantation is a promising therapeutic resource. Superparamagnetic iron oxide nanoparticle (SPION) cell labeling assists HCEC transplantation by attaching the posterior corneal stroma in ex vivo animal models. However, possible functional changes of the HCECs following SPION labeling remain to be determined. In this study, we used SPIONs to label cultured rabbit CECs (RCECs) in order to observe important cell functions and the levels of cell markers. The synthetic SPIONs exhibited superparamagnetism at room temperature, with saturation magnetization of 55.4 emu/g and negligible remanence or coercivity. The ζ-potential was -24.5 mV and the diameter was 101 ± 55 nm. Immunostaining demonstrated a normal density of zonula occluden-1 (ZO-1), nestin and Ki-67 at cellular junctions or in nuclei from RCECs following SPION labeling at 16 µg/ml. MTT cytotoxicity assay, homotypic adhesion assay, quantitative flow cytometric Ki-67 analysis and RCEC pump function measurement demonstrated no significant differences between the cells with or without SPION labeling (P<0.05, for all assays). Results of this study demonstrated successful labeled cultured RCECs with synthetic SPIONs. Labeled cells possessed several important characteristics required to maintain the transparency and refractive parameters of the cornea, including hexagonal cell morphology, higher cell adhesion ability and proliferative potential, cell pump function and the positive expression of several cell markers.

Toward zero effective phacoemulsification time using femtosecond laser pretreatment

OBJECTIVE

To compare effective phacoemulsification time after femtosecond laser pretreatment with conventional phacoemulsification and the associated effect on visual outcomes and endothelial cell loss.

DESIGN

Prospective, consecutive, single-surgeon case-control study.

CONTROLS

Controls underwent phacoemulsification cataract extraction plus insertion of an intraocular lens (IOL). Cases underwent pretreatment with the femtosecond laser followed by phacoemulsification cataract extraction and IOL insertion.

METHODS

Two hundred one eyes underwent cataract surgery between April 2012 and July 2012. Data collected included patient demographics, preoperative characteristics, femtosecond lens fragmentation method, effective phacoemulsification time (EPT), intraoperative complications, and postoperative outcomes.

MAIN OUTCOME MEASURES

Effective phacoemulsification time, intraoperative complications, corneal endothelial cell loss, as well as postoperative best-corrected visual acuity, intraocular pressure, and refractive outcomes.

RESULTS

Patient demographics were similar between groups. There was no difference between baseline cataract grades (2.59 ± 0.71 vs. 2.52 ± 0.72, not significant). One hundred percent of cases pretreated with the femtosecond laser had complete capsulotomy. Mean EPT was reduced by 83.6% in the femtosecond pretreatment group (P<0.0001) when compared with controls, with 30% having 0 EPT (P<0.0001). Effective phacoemulsification time was reduced 28.6% within the femtosecond group using improved lens fragmentation algorithms, and a further 72.8% reduction was achieved with a 20-gauge phacoemulsification tip. Overall, there was a 96.2% reduction in EPT between controls and the optimized femtosecond pretreatment group. This was associated with a 36.1% reduction in endothelial cell loss in the femtosecond group. Visual and refractive outcomes were similar to those of conventional cataract surgery.

CONCLUSIONS

Femtosecond laser pretreatment results in a significant reduction in effective phacoemulsification time, including the possibility of 0 EPT. Further reductions may be achieved using optimization of lens fragmentation patterns and surgical technique.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Cataract surgery in patients with corneal disease

PURPOSE OF REVIEW

Preexisting corneal disease can be exacerbated by cataract surgery and may prevent well tolerated cataract extraction. This article reviews the current literature and describes how corneal epithelial, stromal and endothelial disease may impact and be impacted by cataract surgery while highlighting recommendations for perioperative management and surgical technique.

RECENT FINDINGS

Modifications to surgical techniques can allow for improved intraoperative visualization and safer cataract removal. Cataract surgery can be safely performed in conjunction with newer forms of corneal transplantation such as deep anterior lamellar keratoplasty and endothelial keratoplasty; however, guidelines for when to perform combined surgery have not been established.

SUMMARY

Appropriate perioperative management and advances in surgical techniques and technologies allow for successful cataract surgery in patients with corneal disease. Signs of corneal disease should be identified preoperatively to allow for surgical planning and optimal visual outcomes.